/*
 * Copyright (c) 1999-2003, Carnegie Mellon University. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * 3. Products derived from the software may not be called "iVProg",
 *    nor may "iVProg" appear in their name, without prior written
 *    permission of Carnegie Mellon University.
 * 
 * 4. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes software developed by Carnegie Mellon University"
 */

package edu.cmu.cs.stage3.alice.core.question;

import edu.cmu.cs.stage3.alice.core.Element;
import edu.cmu.cs.stage3.alice.core.Expression;
import edu.cmu.cs.stage3.alice.core.Property;
import edu.cmu.cs.stage3.alice.core.property.OverridableElementProperty;
import edu.cmu.cs.stage3.alice.core.property.StringProperty;

public class PropertyValue extends edu.cmu.cs.stage3.alice.core.Question {
 private boolean m_ignorePropertyChanges = false;
 public final OverridableElementProperty element = new OverridableElementProperty( this, "element", null );
 public final StringProperty propertyName = new StringProperty( this, "propertyName", null );
 private void updateOverrideValueClass() {
  Class elementOverrideValueClass = null;
  String propertyNameValue = propertyName.getStringValue();
  if( propertyNameValue!=null ) {
   Element elementValue = element.getElementValue();
   if( elementValue!=null ) {
    Property property = elementValue.getPropertyNamed( propertyNameValue );
    if( property != null ) {
     elementOverrideValueClass = property.getDeclaredClass();
    } else {
     if( elementValue instanceof Expression ) {
      Class cls = ((Expression)elementValue).getValueClass();
      if( cls != null ) {
       elementOverrideValueClass = cls;
      }
     }
    }
   }
  }
  element.setOverrideValueClass( elementOverrideValueClass );
 }
 //Rem @Override
 protected void propertyChanged( Property property, Object value ) {
  if( m_ignorePropertyChanges ) {
   return;
  }
  if( property == element ) {
   updateOverrideValueClass();
  } else if( property == propertyName ) {
   updateOverrideValueClass();
  } else {
   super.propertyChanged( property, value );
  }
 }
 private Property getPropertyValue() {
  if( element.getOverrideValueClass() == null ) {
   updateOverrideValueClass();
  }
  Element elementValue = element.getElementValue();
  String propertyNameValue = propertyName.getStringValue();
  if( elementValue != null && propertyNameValue != null ) {
   return elementValue.getPropertyNamed( propertyNameValue );
  } else {
   return null;
  }
 }

 //Rem @Override
 public Object getValue() {
  Property property = getPropertyValue();
  if( property != null ) {
   return property.getValue();
  } else {
   throw new RuntimeException();
   //return null;
  }
 }
 //Rem @Override
 public Class getValueClass() {
  Property property = getPropertyValue();
  if( property != null ) {
   return property.getValueClass();
  } else {
   String propertyNameValue = propertyName.getStringValue();
   if( propertyNameValue != null ) {
    Class cls = element.getValueClass();
    if( edu.cmu.cs.stage3.alice.core.Element.class.isAssignableFrom( cls ) ) {
     try {
      java.lang.reflect.Field field = cls.getField( propertyNameValue );
      if( field != null ) {
       return Element.getValueClassForPropertyNamed( field.getDeclaringClass(), propertyNameValue );
      }
     } catch( java.lang.NoSuchFieldException nsfe ) {
      //pass
     } catch( java.lang.SecurityException se ) {
      //pass
     }
    }
   }
   return Object.class;
  }
 }
}
